In this research, flat rolling process of bonded sandwich sheets is investigated by the method of upper bound. A kinematically admissible velocity field is developed for a single layer sheet and is extended into the rolling of the symmetrical sandwich sheets. The internal, shear and frictional power terms are derived and they are used in the upper bound model. Through the analysis, the rolling ...

in the last decade, decrease of the wear rate, increase in the axel load, and the velocity of the trains have changed the main damage mechanism of railway wheels from wear to rolling contact fatigue (rcf). rcf may lead to surface and subsurface cracks. the interaction between wear and rcf, removes the surface cracks, but the subsurface crack propagate gradually, and may lead to deeper and more ...

We study a class of problems involving the motion of a linear elastic body in frictional contact with a linear elastic half space. The dynamic effects considered are the inertial properties of the body regarded as rigid. We study only those regimes of contact interaction for which the slip velocity with the body taken as absolutely rigid and the time rate of change of the elastic displacements ...

in this work, improved heat generation models are developed for straight and tapered shoulder geometries with different tool pin profiles in friction stir welding. the models are developed considering the welding process as a combination of the pure sliding and the pure sticking conditions. from the results, the amount of heat generation is directly proportional to the number of edges in the pi...

Carbon nanotubes (CNTs) are well known for their exceptional thermal, mechanical and electrical properties. For many CNT applications it is of the foremost importance to know their frictional properties. However, very little is known about the frictional forces between an individual nanotube and a substrate or tip. Here, we present a combined theoretical and experimental study of the frictional...

Abstract Railway wheels in service experience rolling contact fatigue loading, but also need to resist frictional heating on braking, yielding temperatures up 500 °C. The combination of mechanical and thermal loads leads changes the properties material. focus this study is investigate effect annealing local microstructure residual stresses railway wheel pearlitic steel (medium carbon steels, ~0...

A 3-dimensional finite element algorithm for modeling nonlinear frictional contact behaviours between deformable bodies with the node-to-point contact element strategy has been proposed and applied here to investigate stress evolution processes of a nonlinear frictional contact system. The numerical results of a typical intra-plate fault bend model demonstrate the efficiency and usefulness of t...

This paper presents a novel approach for grasp optimization considering contact position and object information uncertainties. In practice, it is hard to grasp an object at the designated or planned contact positions, as errors in measurement, estimation, and control usually exist. Therefore, we first formulate the influences of contact uncertainties on joint torques, contact wrenches, and fric...

Abstract The thermal shock of subsurface material with shear instability and severe plastic flow during scuffing was investigated. damage M50 steel tested using a high-speed rolling—sliding contact test rig, the transient temperature calculated Fourier transform method considering effects both frictional heat work. results show that rapid rise subsequent decrease in is generated layers. power i...

By theoretically analyzing dynamic behavior of the crankshaft, the rolling piston and the blade inrolling-piston rotary compressors, constraint forces and sliding speed at each pair of movable machine elements were obtained, and unbalanced inertia forces and compressor vibrations were evaluated. It was concluded that theoretical results have a goodagreement with experimental ones. Moreover, it ...